[Perf] Disable startup.mobile/cct:coldish:bbc

Disable failing perf story startup.mobile/cct:coldish:bbc on two
Android platforms:
* https://ci.chromium.org/p/chrome/builders/ci/Android%20Nexus5%20Perf
* https://ci.chromium.org/p/chrome/builders/ci/android-pixel2-perf

Notry: true
TBR: wenbinzhang@google.com
Bug: 1142286
Change-Id: Ie742c8570505bcf100b804ed4686285143aebf5a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2570857Reviewed-by: John Chen <johnchen@chromium.org>
Commit-Queue: John Chen <johnchen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#833188}

tools/perf/expectations.config

@@ -263,6 +263,8 @@ crbug.com/948789 [ android-nexus-5 ] startup.mobile/maps_pwa:with_http_cache [ S
 crbug.com/948789 [ android-nexus-5x ] startup.mobile/maps_pwa:with_http_cache [ Skip ]
 crbug.com/1030735 [ android-weblayer ] startup.mobile/maps_pwa:with_http_cache [ Skip ]
 crbug.com/1059717 [ android-pixel-2 ] startup.mobile/maps_pwa:with_http_cache [ Skip ]
+crbug.com/1142286 [ android-pixel-2 ] startup.mobile/cct:coldish:bbc [ Skip ]
+crbug.com/1142286 [ android-nexus-5 ] startup.mobile/cct:coldish:bbc [ Skip ]
 
 # Benchmark: system_health.common_desktop
 crbug.com/903417 [ mac ] system_health.common_desktop/long_running:tools:gmail-foreground [ Skip ]